Improvement in dentists  chairs



4 Sheets-Sheep B. WILKERSON. Dentsts Chairs'.

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B. M.. IWILKERSON.

Dentists Chairs.

N. PETERS. PHUTQZUTHDGRAPHEH, WASNINGiON. D

. 4Sneens-Sheet 3. B'. M. WILKERSON. Dentists Chairs.

Patented Nov-.E2O, 1877.

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4 Sheets-Sheet 4.

B. WILKERSON.

Dentists Chairs. l No.197,441. Patented Nov. 20,1877.

a f r r 4 N. PETERS, lPH0IO-LXI'HOGRAF'MEn, WASHINGTON, D C.

UNITED ESTATES BAsrL M. wrLxEns'oN, oEBALTrMoEE, MARYLAND.

IMPROVEMENT IN DENTIsTsJ CHAIRS.

Specification forming part of Letters Patent No. 197,441, dated November 20,

April 17, 1877.

1877 application iiled To all whom-lt may concern:

Be it known that I, BAsiL M. WrLKERsoN, 0f the city of Baltimore, State of Maryland, have invented certain new and useful lmprovements in Dental Chairs; and I hereby declare the same to be fully, clearly, and exactly described as follows, reference being had to the accompanying drawings, in whichvFigure `l represents a side lelevation of my improved chair 5 Fig. 2, a plan view ofthe same, having the chair-seat removedwFigsfS to 27, inclusive, represent enlarged views of various parts of the chair.

Similar letters of reference indicate similar parts in all the figures.

This invention relates, as stated, to dental chairs, and `it consists in certain details of the same, and combinations of parts not here necessary to enumerate, as they are hereinafter made the subjects of claims based upon the following description.

sA represents a hollow cylindrical pedestal,

' supported, preferably, upon three legs, A',

projecting radially' therefrom, anda fourth leg, A", the foot of which is raised slightly above the plane of the remaining three feet, and is provided with a screw, c, on the under side, which is raised or lowered, as the case may be, in order to adjust the chair to suit irregularities in the floor. ranged as indicated 1in the drawings, the leg A projecting toward the front, and being designed to prevent the tilting forward of the chair as the patient steps upon the foot-bpard, while the adjacent legs A', on either side, project forward of the medianline ofthe chair in order to be out of the way of the feet of the operator. The back leg A extends centrally to the rear. Byv this arrangement of the legs a large space is left on each side of the central back leg free to be used, without obstruction or hinderance, by the operator, who, heretofore, during his work, has frequently been impeded and annoyed by the legs, which, in ordinary chairs, extend from the corners of the chair.

B represents a cylindrical liquid-reservoir,

constructed to rest and turn within the p edes tal` A. A set-screw, b, Figs. l and 3, 1s in. serted through the shell of the pedestalagainst p the exterior of thecylindrical reservoir, and is provided with a lever, c, extending nearly to These legs are ar-` PATENT OFFICE.'

the floor, and within convenient reach of the foot of the operator. Upon turning the lever c the screw bis brought to bear upon the cyl-- inder, and prevents its revolution. (l is a cylinder formed within as a part of the reservoir der. A. partition, c', in the lower part of the reservoir, and situated a short distance from the lower head of the same, serves, in connec-v tion therewith, to forma chamber, c", with which the lower end of the cylinder communicates. Two valves, d d', Figs. 3 and 4, are located in the partition c', and open into the chamber c. rlhese valves control the only means of access from the cylinder below the plunger to the reservoir/ B, and subserve an end hereinafter more particularly described.

The plunger C constitutes the support upon which the chair-body rests, and carries, at its upper extremity, a bar, f, upon which the chair-body is pivoted. The plunger is adapted. to be elevated by means of a foot-lever, D, hinged to the upper part of the reservoir, and having upon its inner extremity a spring-pawl, d, which engages with a series of recessed teeth upon the plunger. The lever is caused,

after each stroke, to assume its no mal posil? tion through the agency of a sprin `connect-L ing the lower end of the pawl with the lower part of the reservoir. At the same time a projection, w, on the inner face of the lower partof the pawl strikes the upper edge or shoulder of the cylinder, and is thereby thrown out of engagement. Thus the lifting mechanism,

when in the normal position to which it is returned by the action of the spring, is entirelyv disengaged anddisconnectedfrom the plunger.

The reservoir above described contains glycerine, oil, or other suitable liquid, which follows the lplunger during its ascent, and

prevents the descentof the same, owing tol the closure of the valves d d. The liquid that thus follows the plunger is supplied fromthe reservoir through the` larger valve d, which automatically opens to permit passage of the I liquid into the plunger-cylinder. To lower the chair-body, it is obviously only necessary to open 'the valve el and allow theliquid to ilow back to the reservoir, which, owing to the comparatively small size of the valve d', leaves the plunger-cylinder more slowly than it entered through the large valve d. This arrangement permits of the rapid elevation of the chair, and at the same time insures that it shall descend gradually and without shock. The pawl being out of gear, as above described, the. plunger freely follows the liquid. Y

In order to open the valve, any convenient mechanism may be used. The means I have adopted consists of a wire connecting the valve with a lug, e, on the set-screw e. (See Figs. 4 and 7.) This set-screw carries also a griping device, e", and has attached to its guter end a foot-lever, 6'. (See Figs. 1, 2, 4.) By turning the lever in one direction the valve is opened by means of the wire and lug e'. By turning it in the other the plunger is firmly clamped and held in position. A chain co'nnects the lever 6 with the outer or swinging end of the foot-lever D, and is of such` a length that the bringing of the foot-lever into position for elevating the plunger necessarily releases the griping device. V

When not in use, the lever D is swung around out of the way o f the operator. For

this purpose the lever, as shown in Figs. 3 and 7, is made in sections (in this instance two sections) jointed together at D1, so that the outer section can be turned on its `hinge toward the chair, or rearwardly toward the chair and out of the way. A projection, D2, on the outer section brings up against a stop von the inner section, when. the lever is straightened out in position foruse.

The chair-body is nearly balanced upon the bar f, `and hence no especial mechanism is necessary in order to tilt the chair, but a slight exertion on the part of the operator suicing to effect this end.

The mechanism for retaining the chair-body i firmly in position atany angle is illustrated in Figs. 1,2, and 19, and consists of a curved perforated bar, g, secured to some part of the chair-body, and a spring bell-crank, g/pivoted tothe bar f. The short arm of the crank ishinged. to a tapering bolt, g, which slides through a part of the bar j', and is projected into the perforation inthe bar g, which falls opposite.

The object in forming the bolt g tapering is toymalre aperfectly rigid fastening, and

\ while seated in the chair.

E E'7 Figs. `12, 15, 16, represent, respectively,

the upper and lower xed foot-boards, the intervenin g space being occupied by the tilting foot-board F, hinged to the chair-frame. The

mechanism for elevating this foot-board is illustrated in Figs. 15 and 16, and consists of the following elements: The inner sides Aof the chair-frame are furnished with slotted bars 13, the upper sides of which are fitted with ratchet-teeth, with which pawls i', formed on or .rigidly fixed to the ends of a crank-rod, i, are

adapted to engage. AV foot-piece, i, is attached to the crank-rod outside the chairframe, the rod also carrying one or more arms, k, loosely attached to the under side of the tilting foot-board.

The pawls i are normally in gear with the ratchet, but the motion ofthe foot-piece 1"" in the direction indicated by the arrow releases them, and admits of the elevation of the footb'oard. In this operation the footpiece, in practice, is usually first slightly tilted so as to take the pawls out of engagement with the ratchets, and simultaneously with` this movement the foot-piece, by a direct thrust of the foot, is pushed forward, traveling in the line of the slots, and, of course, carrying forward by a foot-bar, F', considerablyshorter than l the width of the chair-body, in order to enable the chair to be revolved in a limited space.

The movable back G of the chair is attached to the frame by means of tongues and grooves, (see Figs. 1, 2, 13, 14, 18,) and is held at any desired elevation by means of bolts l, simultaneously projected outward by the revolution of a double cam, lf, operated by -means of a handle upon the movable back.,` This handle also serves as a means for elevating and vlowerin g the movable back, and enables the operator to accomplish this by the use of one hand.

A supplemental or childs seat, Gr, (see Fi gs.1, 2, 17 and'f18,) is pivoted totheupper ends of'tlie iixed chair-frame, and when extended for use i -is supported by bars pivoted to its sides. The

said bars have pins l at'their lower ends,

`which slide in grooves in the chair-frame, as

shown, the grooves terminating in slots for sustaining the seat when extended. porting-barsare prolonged above thechilds seat, and constitute its arms. childs seat is folded it forms a cushion for the back of the adult patient. `The chair-frame being provided `with a spring, l', Fig. 17, into When the' The supcontact with which the childs seat comes when folded, the latter is made to bear with a yielding pressure against the back of the pa-` links.

tient. VThe head-rest is secured to the upper end of the extensible back, and is illustrated in Figs. l, 2, 20, 2l, 22, 23, 24, 26, and 27.

A head-piece, H, formed of a curved plate,

m, is provided with a shank extending from its lower edge, and is cushioned and upholstered as hereinafter described. The shank terminates in a ball, m, which is confined in a socket of like shape in the first of a series of The latterconsists `of an elongated open block, m, Figs. 20, 21, 22, in which slides a central block, m", and the socket in which the spherical knob rests is divided equally between the twe. The other end of this link is provided with a tapering hole, situated similarly with reference to the two blocks, the hole being occupied by the upper cone of the pivot n n. The lower cone n fits in oneend of a second link similar in construction to the one just described. The other end of this link receives the conical head of a bar, n, and its under side is in contact with a collar on asecond bar, u, through which collar the bar n" passes.

The bars are provided with teeth on their opposing faces, a slight longitudinal motion of the bars in opposite directions being required to bring theteeth fully in gear. (See Figs. l and 20.) The bars are inserted in the upper end of the extensible back of the chair, and -between a cam, ne, operated by a handle and a portion of the said back. iThe entire head-rest mechanism may be elevated and depressed as desired, and is secured in position by means of the cam, as shown in- Fig. 420. Itisobvious, from the conformation of the parts, that a single motion of the cam secures all the j oints-a highly important feature, as it saves the time necessary to secure the various thumbscrews heretofore used with head-rests.

The several links that form the variable vhead-rest support are connected together and to the chair frame by vertical pivots. The devices which connect them are cones, each of which fits in a tapering socket capable of expansion andcontraction. The locking movementof the c am n* causes a downward movement of bar n2; this pulls down the cone on the upper end of the bar into its sockenand so, by expanding the socket, pushes outwardly the movable block that forms one half of the socket. 'But this block, at its opposite end, forms a part of the tapering socket of cone n,and its movement, consequently, causes a contraction of said socket, and so forces downward the cone nf, which consequently draws downthe upper cone n into 'its socket; and the expansion of the socket of cone a has the effect, through the medium of sliding block m", of contracting the spherical socket of the ball m. Thus are all these joints stiffencd and locked by a slightmovement of a single cam. A reverse movement of thecam will unlock the joints and leave the several links free to move.

A swinging arm-rest, Figs. 26, 27, is pivoted to the back of the curved plate m, its pad or arm-rest proper` swivelin g freely at the end rlhe cushion of the head-piece consists of two pads, o o, connected by means of a slackstrap, of.

The Waterreservoir, spittoon, instrumenttrays, &c., are connected to the. chair as follows: A rod, p, is secured to the bar f by means of a pin, p', and swings freely, as shown in dotted lines in Fig. 2. A tubular rod, p, is sef cured to the end of the rod p, in which tube the rod p supporting the reservoir, is adapted to slide. The reservoir K is susceptible of a rotary or circumferential motion on the rod 15 as an axis, in common withits supportingl bar, and independent of the swinging bar p and its vertical tubular extension p. The

reservoir is made vertically adjustable by means of a collar, r, on the rod 10', the collar being provided with a thumb-screw, r. The part of the rod p between the reservoir and the pipe 1^ is tubular, 'and constitutes a duct i for the passage of the water tothe annular space rf" around the rim of the funnel -s. A

valve s" controls the exit from the reservoir being opened by means of a wire leading to the top of the latter.

A pipe, s", leading from the reservoir, is used f in drawing drinking-water, and a tray, 8', for Y a tumbler isattached-to the pipe r". The 'pipe s. is provided with a valve operated by means of a sleeve, t, on the lower end of the pipe, connected to the valve through the medium of a wlre.

To a revolving sleeve on the rod p is secured an arm, t', supporting vthe standard t for the instrument-trays.

and areiitted to turn 'in any direction. Any suitable device may be employed to secure the arm t to the standard. A convenient means is shown in Fig. ll.

The spittoon-bowl o is detachable from the funnel s, and to this end is provided with pins A 'v' projecting from v its outer edge, the same being inserted in slots on the upper part of .the bowl, the entrance being by means of notches '17". (See Fig. l0.) A gold-trap, L, is

suspended within thebwl of the spittoon, and directly below the neck of the funnel, by means of wires extending from a ring, '12'. By raising the ring the trap may be readily removed.

Handles M, on either side of the-chair, are

designed for use by the patient during painful or violent operations. Afoot-stool, N, is piv-` oted to one ofthe legs Af, and a seat, O, is secured to the chair-frame, for they use of the operator.

My design has been to 'furnish a dental chair A vertically-adjust n ablev arm, tf, 4extendingfron'i the polygonal l notched standard t", carriesa difierentiallycollared stud, u, upon which the trays u rest,

nected to the fixed frame by tongues and grooves, and provided with a locking device which constitutes a handle for elevating it,

- an adult patient, substantially as described.

21. In combination with a dental chair, a f. supplemental or childs seat, pivoted to the back or body of the chair, and adapted, when v dental chair, an arm-support for the operator,

folded down, to form a supporting device for the back of the adult patient, substantially as set forth.

22. The supplemental or childs seat having its supports extended above the seat when opened in order to form arms therefor, substantially as set forth.

23. In a dental chair, a head-rest pivoted twice about parallel axes and once about a ball-and-socket joint, as set forth.

24. A head-rest support formed of links or sections united 'by conical or tapering pivots seated in correspondingly-shaped sockets capable of expanding and contracting, and bounded, in part, by movable blocks which transmit the movement from one cone and socket to the next throughout the series, whereby the several joints will be tightened by the operation of a single device, substantially as set forth.

25. In combination with the head-rest of a substantially as described.

- 26. In a dental chair, an arm-rest adapted to be secured at either side of the head-rest, substantially as described.

27. In combination with the head-rest of. a dental chair, a swiveling arm-rest, substantially as described.

28, Aheadrest for a dental chair consisting of a pair of pads connected by means of a slack strap, as set forth.

29. In combination with a dental chair, a spittoon pivoted twice about vertical axes, whereby it may be made to occupy any position within the circle described by the extreme radius of the supporting-arms, substantially as described.

30. The combination, with the spittoon of a dental chair, of a water-reservoir connected with and carried by the chair, and adapted to deliver a supply of water to the spittoon, for

lthe purpose set forth.

the purpose of rinsing the same, substantially as set forth.

31. In combination with the spittoon of a dental chair, a water-reservoir adapted to deliver a supply of water through an annular opening near the rim of the spittoon, substantially asdescribed.

32. A trap suspended within a spittoon by means of wires attached to a removable ring of greater diameter than the neck of the spittoon, substantially as described. f

33. In combination with a dental chair, a` foot-stool for the operator, attached thereto, substantially as described.

34. A support for a dental chair consisting of three legs radiating from a common center,

at equal distances apartfthe back leg extend-` ing rearward centrally of the chair, in combi. nation with a fourth radial leg extending directly to the front, and bisecting the angle formed by the two side legs, as set forth.

35. In combination with the water-reservoir K, a cock consisting of the tube s, having at its inner end a valve operated by a sleeve resting over the outer end of said pipe, and a v.

wire passing within the same and attached to the valve, as described.

36. The combination of the water-reservoir K, having a pipe the opening of which is controlled by avalve combined with the funnel s, having the annular opening r, communicating with the supply-pipe leading from the reservoir, all substantially as described, and for 37. The combination, substantially as set forth, with the seat-supporting plunger, its cylinder or sheath, and the elevating mechanism, of the iluid-reservoir provided with a large inlet-valve, which permits the fluid to/L follow a rapid ascent of the plunger, and a smaller outlet-valve, which permits the iiuid tol be displaced by the descending plunger slowly, so as to insure the gradual and easy descent of the chair-seat.

38. The plunger-cylinder arranged within v scribed my name this 16th day of April, A. l).

v BASIL M. WILKERSON.

Witnesses -WM. S. HOWARD,

Gr. E. SANGsTER. 

